Demand for semiconductor devices for lower-cost, higher performance, increased miniaturization and greater packaging densities have lead to MCM structures. MCM structures include two or more die and optionally other semiconductor components mounted within a single semiconductor package. The number of dies and other components can be mounted in a vertical manner, a lateral manner, or a combination of a vertical and lateral manner.
One arrangement of first and second power MOSFETs (hereafter a “power FET”) is implemented as stacked lateral power FETs. Stacked lateral power FETs are conventionally assembled by placing one leadframe matrix subassembly having one power FET soldered thereto on top of another leadframe matrix subassembly having another power FET soldered thereto. Challenges in such assembly include reducing the movement between the two subassemblies prior to reflowing the solder and insuring flatness between the two subassemblies to provide good interconnection all at once during solder reflow.